UPSC Prelims 2024— Question 68

The correct answer is option (C). Pumped-storage hydropower stores energy by using electricity to pump water to an upper reservoir and later releasing it through turbines. It therefore functions as a form of long-duration energy storage and helps balance variable renewable generation. The key to this question is to distinguish the exact constitutional provision, factual association, scientific principle, or current-affairs detail being tested from statements that are partly true but incomplete or incorrectly framed. UPSC often makes the distractors plausible by changing one institutional role, date, classification, geographic association, or causal relationship. Option A — “Irrigation of terraced crop fields” is incorrect. It does not match the established fact or contains the incorrect combination, institution, relationship, classification, or proposition identified in the explanation above. Choosing it would therefore introduce a factual error or omit a necessary element. Option B — “Lift irrigation of cereal crops” is incorrect. It does not match the established fact or contains the incorrect combination, institution, relationship, classification, or proposition identified in the explanation above. Choosing it would therefore introduce a factual error or omit a necessary element. Option C — “Long duration energy storage” is correct. It matches the established fact described above and gives the complete combination or identification required by the question. Option D — “Rainwater harvesting system” is incorrect. It does not match the established fact or contains the incorrect combination, institution, relationship, classification, or proposition identified in the explanation above. Choosing it would therefore introduce a factual error or omit a necessary element. For examination purposes, the safest approach is to verify each statement independently before looking at the answer-code combination. This is particularly important in statement-based questions, because one false clause makes an entire combination wrong. In factual questions, compare the defining characteristic asked in the stem with each alternative rather than relying on superficial familiarity. The answer recorded here follows the verified Set C key used for this database.